@@ -7,7 +7,7 @@ NL
 end JMPw
 
 ; Factorial subroutine
-; a16 -- | [xy]
+; a16 -[xy]-
 .label fact
   ; Save argument to both registers
   POPxyw

@@ -7,7 +7,7 @@ NL
 end JMPw
 
 ; Factorial subroutine
-; a8 -- | [xy]
+; a8 -[xy]-
 .label fact
   ; Save argument to both registers
   POPxy

@@ -1,7 +1,7 @@ 
-.include "lib/macros.xyw"
-
 ;;; Korobeiniki - Traditional Russian folk song
-;;; Main melody - "Type A"  Tetris Theme
+;;; Main melody - "Type A"  (Tetris Theme)
+
+.include "lib/macros.xyw"
 
 ; note duration macros
 .macro n2 $00C0 ; half note

@@ -10,10 +10,10 @@ .macro system.random          $05
 .macro system.on_error        $06
 
 ;terminal
-.macro terminal.input          $10
-.macro terminal.output         $11
-.macro terminal.on_keypress    $12
-.macro terminal.on_argument    $14
+.macro terminal.input         $10
+.macro terminal.output        $11
+.macro terminal.on_keypress   $12
+.macro terminal.on_argument   $14
 
 ;clock
 .macro clock.year             $20
@@ -44,10 +44,11 @@ 
 ;;; Utilities
 .macro MOD DIV POP
 .macro LBYTE SWP POP
-.macro PUTC $11 STB
+.macro PUTC terminal.output STB
 
 ;;; ASCII Characters
 .macro NL $0A PUTC
+.macro CR $0D PUTC
 .macro SP $20 PUTC
 
 ;;; Argument separators
@@ -55,14 +56,14 @@ .macro arg.sep $1E
 .macro arg.end $1D
 
 ;;; Errors
-.macro error.file.not_found $31
+.macro error.file.not_found     $31
 .macro error.file.access_denied $32
-.macro error.file.invalid_op $33
-.macro error.file.io_error $34
+.macro error.file.invalid_op    $33
+.macro error.file.io_error      $34
 
 ;;; File operations
-.macro file.op.read $01
-.macro file.op.write $02
+.macro file.op.read   $01
+.macro file.op.write  $02
 .macro file.op.append $03
 .macro file.op.delete $04
 

@@ -1,7 +1,7 @@ 
 ; .include "lib/macros.xyw"
  
 ; Print an 8bit integer as decimal
-; a8 -- | [x]
+; a8 -[x]-
 .label putd
   POPx 
   ; If value is less than 10, print single digit

@@ -1,7 +1,7 @@ 
 ; .include "lib/macros.xyw"
 
 ; Print a 16bit integer as decimal
-; a16 -- | [x]
+; a16 -[x]-
 .label putdw
   POPxw 
   ; If value is less than 10, print single digit

@@ -1,7 +1,7 @@ 
 ; .include "lib/macros.xyw"
 
 ; Print a string starting at address
-; a16 -- | [xw]
+; a16 -[xw]-
 .label puts
   POPxw
   .label puts.loop

@@ -8,6 +8,7 @@ $10 $00 DIV
 end JMPw
 
 ; on error handler
+; --
 .label on_error
   system.error LDB $01 EQU on_error.div-by-zero.print JCNw
   unknown-error puts JSRw

@@ -6,6 +6,7 @@ ; End program
 end JMPw
 
 ; on_argument event handler
+; -[x]-
 .label print-args
     terminal.input POPx
     ; If end of argument, print new line and end
@@ -13,15 +14,18 @@ LDBx arg.end EQU print-args.end JCNw
     LDBx arg.sep EQU print-args.next JCNw
     ; Print typed character
     LDBx PUTC
+    CLRx
     RTS
     ; Print argument separator (, )
     .label print-args.next
         $2C PUTC
         SP
+        CLRx
         RTS
     ; Print new line
     .label print-args.end
         NL
+        CLRx
         RTS
 
 .label end

@@ -7,6 +7,7 @@ ; End program
 end JMPw
 
 ; on_keypress event handler
+; --
 .label print-key
     ; Print typed character
     terminal.input LDB PUTC

@@ -1,7 +1,5 @@ 
 .include "lib/macros.xyw"
 
-.macro CR $0D PUTC
-
 ; Main program
 print-clock JSRw
 set-timer JSRw
@@ -42,11 +40,12 @@ ZEROPADx JSRw
   RTS
 
 ; Print an 8bit integer as decimal, with leading zero if less than 10
-; a8 -- | [x]
+; a8 -[x]-
 .label ZEROPADx
   POPx PSHx $0A LTH put-zero JCNw
   .label put-digit
     PSHx putd JSRw
+    CLRx
     RTS
   .label put-zero
     $30 PUTC